CODE-F AIPMT – 2015 TEST PAPER WITH SOLUTIONS (HELD ON SUNDAY 03th MAY, 2015) 1. The reaction of C6H5CH = CHCH 3 with HBr produces:(1) C6H5CH 2CHCH3 (2) C6H5CH2CH2CH2Br Br CH=CHCH3 (3) (4) C6H 5CHCH2CH3 3. The Ksp of Ag2CrO 4, AgCl, AgBr and AgI are respectively, 1.1 × 10–12, 1.8 × 10–10, 5.0 × 10–13, 8.3 × 10–17. Which one of the following salts will precipitate last if AgNO3 solution is added to the solution containing equal moles of NaCl, NaBr, NaI and Na2CrO4 ? (1) AgCl (2) AgBr (3) Ag2CrO4 (4) AgI Ans. (3) Sol. Br Br Þ ëé Ag+ ûù = Ans. (4) éëCrO ùû -2 4 = 1.1 ´ 10-12 m éëCrO4-2 ùû = max CH CH Å CH EN C6H5 4. Bithional is generally added to the soaps as an additive to function as a/an :(1) Dryer (2) Buffering agent (3) Antiseptic (4) Softner Ans. (3) Sol. Bithionol (the compound is also called bithional) is added to soaps to impart antiseptic properties CH3+HBr CH2 CH3 Br CH CH2 CH3 LL C6H5 Br A In Duma's method for estimation of nitrogen, 0.25 g of an organic compound gave 40 mL of nitrogen collected at 300 K temperature and 725 mm pressure. If the aqueous tension at 300 K is 25 mm, the percentage of nitrogen in the compound is :(1) 18.20 (2) 16.76 (3) 15.76 (4) 17.36 Ans. (2) Sol. Volume of nitrogen collected at 300 K and 725 mm pressure is 40 mL actual pressure = 725 – 25 = 700 mm 273 × 700 × 40 = 33.52mL = 300 ´ 760 22,400 mL of N2 at STP weight = 28 g 33.5 mL of nitrogen weight = Percentage of nitrogen 28 ´ 33.52 ´ 100 = 16.76% 22400 ´ 0.25 5. Cl OH HO Cl S Cl Cl Bithionol "Metals are usually not found as nitrates in their ores". Out of the following two (a and b) reasons which is/are true for the above observation ? (a) Metal nitrates are highly unstable. Volume of nitrogen at STP = K sp so answer is Ag2CrO4 Sol. C H 6 5 2. 2 Ag2 CrO 4 ® K sp = ëé Ag + ûù ëéCrO4-2 ûù 28 ´ 33.52 g 22400 (b) Metal nitrates are highly soluble in water. (1) a and b are false (2) a is false but b is true (3) a is true but b is false (4) a and b are true Ans. (2) Sol. Metal nitrates are stable like NaNO3 and KNO3 and highly soluble in water. 1 AIPMT-2015 6. The correct bond order in the following species is:+ (1) O2+ 2 < O2 < O2 (2) O+2 < O2- < O2+ 2 (3) O2- < O2+ < O2+ 2 + (4) O2+ 2 < O2 < O2 Ans. (3) Sol. No. of e - No. of e - O2+ O2+2 17 15 14 The species Ar, K+ and Ca2+ contain the same number of electrons. In which order do their radii increase ? (1) Ca2+ < Ar < K+ (2) Ca2+ < K+ < Ar (4) Ar < K+ < Ca2+ An organic compound 'X' having molecular formula C5H10O yields phenyl hydrazone and gives negative response to the Iodoform test and Tollen's test. It produces n-pentane on reduction. 'X' could be :(1) 2-pentanone (2) 3-pentanone (3) n-amyl alcohol (4) pentanal Ans. (2) Ph—NH—NH2 Sol. (1) T In K vs.T vs. l T (2) In K vs. l Ans. (2) Sol. Arrhenius equation K = A.e - Ea/RT Þ lnK = lnA - 9. Ea RT (3) 2 1 T ClO3- ,SO23 - (2) SO23 , NO3 (4) n-pentane According to questions CH3 CH2 C CH2 CH3 O does not give iodoform as well as Tollen’s test H3C CH2 C CH2 CH3 O reduction CH3—CH2—CH2—CH2—CH3 Zn-Hg/HCl n-pentane — or NH2-NH2/OH Which of the following options represents the correct bond order ? (2) O -2 > O2 < O2+ (3) O -2 < O2 > O+2 (4) O -2 > O2 > O 2+ Which of the following pairs of ions are isoelectronic and isostructural ? (1) ClO -3 ,CO32 - 11. Negative (1) O -2 < O2 < O +2 so, activation energy of reaction can be determined from the slope of lnK vs Tollen's test T (4) In K vs. T A (3) T LL The activation energy of a reaction can be determined from the slope of which of the following graphs ? Phenyl hydrazone I2 + NaOH Negative Iodoform test Reduction hence increasing order of radius is Ca+2 < K+ < Ar In K sp3 both are having one lone pair on central atom hence they are pyramidal. X compound (C5H10O) 1 Atomic radius µ Z eff 8. 42 3 EN (3) K+ < Ar < Ca2+ Ans. (2) Sol. In isoelectronic species 42 10. Bond order 1.5 2.5 3.0 7. SO3-2 hybridisation sp Ans. (3) Sol. According to molecular orbital theory (MOT) O2- ClO3- CO23 - ,SO32 - Ans. (1) Sol. According to molecular orbital theory (MOT) No. of e - O2- O2 17 16 15 Bond order 1.5 2 O2+ 2.5 CODE-F 12. O with Treatment of cyclopentanone Sol. FCC : r = 16. methyl lithium gives which of the following species? (1) Cyclopentanonyl cation (2) Cyclopentanonyl radical (3) Cyclopentanonyl biradical (4) Cyclopentanonyl anion Ans. (4) CH3 Å O + CH3Li Sol. 13. NH2 Sol. electrolytic nitrobenzene strongly NH2 rearrangement Phenyl hydroxyl amine OH p-Aminophenol H2 H C = C – C– Cl H (3) H3C H2 H C = C – C– Cl H (4) H3C H2 H C = C – C– Cl H CH CH CH2 Cl Which one of the following electrolytes has the same value of van't Hoff's factor (i) as that of the Al2(SO4)3 (if all are 100% ionised) ? (1) K3[Fe(CN)6] (2) Al(NO3)3 (3) K4[Fe(CN)6] (4) K2SO4 Ans. (3) Sol. van’t Hoff factor of A Magnetic moment 2.84 B.M. is given by :(At. nos, Ni = 28, Ti = 22, Cr = 24, Co = 27) (1) Ti3+ (2) Cr2+ (3) Co2+ (4) Ni2+ Ans. (4) K 4 [ Fe ( CN )6 ] ® 4K + + [Fe ( CN )6 ] hence m = 2.8 B.M., paramagnetic A given metal crystallizes out with a cubic structure having edge length of 361 pm. If there are four metal atoms in one unit cell, what is the radius of one atom? (1) 127 pm (2) 80 pm (3) 108 pm (4) 40 pm Ans. (1) -4 so n =5 Þ i = n =5 number of unpaired electrons (n) =2 Q m = n (n + 2) Al 2 ( SO 4 )3 ® 2Al +3 + 3SO -42 so n = 5 Sol. Ni+2 = 3d8 15. (2) H3C 17. aniline HN OH acidic medium 14. H2 H C = C – C– Cl H Ans. (2) Sol. After leaving Cl–, due to resonance, p bond is also transferred LL reduction (1) H3C H3C weakly acidic medium NO2 361 = 127pm 2 ´ 1.4141 EN The electrolytic reduction of nitrobenzene in strongly acidic medium produces :(1) Azoxybenzene (2) Azobenzene (3) Aniline (4) p-Aminophenol Ans. (4) 2 2 = Which of the following is the most correct electron displacement for a nucleophilic reaction to take place? O cyclopentanonyl anion a 18. Nitrogen dioxide and sulphur dioxide have some properties in common. Which property is shown by one of these compounds, but not by the other ? (1) is a reducing agent (2) is soluble in water (3) is used as a food-preservative (4) forms 'acid-rain' Ans. (3) Sol. NO2 is not used as food preservative. 3 AIPMT-2015 19. The total number of p-bond electrons in the following structure is :H H3C H H CH3 H3C H H2C (1) 8 Ans. (1) Sol. H3C (2) 12 H H CH3 (3) 16 H CH3 H3C H2C H (4) 4 23. The number of d-electrons in Fe2+ (Z = 26) is not equal to the number of electrons in which one of the following? (1) p-electrons in Cl (Z = 17) (2) d-electrons in Fe (Z = 26) (3) p-electrons in Ne (Z = 10) (4) s-electrons in Mg (Z = 12) Ans. (1) Sol. Fe+2 = 3d6 (number of ‘d’ electrons = 6) in Cl = 1s2 2s2 2p6 2s2 3p5 Total p bonds = 4 Total p electrons = 8 24. CH3 20. Solubility of the alkaline earth's metal sulphates in water decreases in the sequence :(1) Ca > Sr > Ba > Mg (2) Sr > Ca > Mg > Ba (3) Ba > Mg > Sr > Ca (4) Mg > Ca > Sr > Ba Ans. (4) Sol. Due to very small size of Mg +2, Mg +2 shows maximum hydration energy. total p electrons = 11, which are not equal to number of ‘d’ electrons in Fe+2 In which of the following compounds, then C - Cl bond ionisation shall give most stable carbonium ion? H H3C Hydration energy Maximum bond angle at nitrogen is present in which of the following ? (1) NO -2 (3) NO3- (2) NO +2 (4) NO 2 O2NH2C Sol. H3C C Cl A ¾¾¾¾¾¾¾ ® The value of K is very high so the system will contain mostly products at equilibrium. 4 H C – Cl H3C H3C C + H3C CH3 t-butyl carbonium ion H NO-2 < NO-3 < NO2 < NO 2+ bond angle If the value of an equilibrium constant for a particular reaction is 1.6 × 1012, then at equilibrium the system will contain :(1) mostly reactants (2) mostly products (3) similar amounts of reactants products (4) all reactants Ans. (2) Sol. The value of equilibrium constant for reaction K = 1.6 × 1012 (4) Cl H3C CH3 Ans. (2) Sol. NO2+ : sp hybridisation (bond angle = 180°) 22. H3C C – Cl H Ans. (2) LL 21. (3) Solubility CH3 H MgSO4 > CaSO4 > SrSO 4 > BaSO 4 CH – Cl (2) EN (1) H3C C – Cl CH Cl H Cl CH Å benzyl carbonium ion [stable due to resonance] H H Cl C Cl O2NCH2 H O2NH2C H H3C H3C -I effect H C Cl CÅ Cl H3C H3C H CÅ Secondary carbonium ion [isopropyl carbonium ion] CODE-F Most stable carbonium ion is benzyl carbocation due to resonance Å CH2 CH2 Å Å Å CH2 CH2 25. CH3 Ph CH3 – C – CH – Ph – C – Ph CH3 (I) (II) – CH3 (III) Sol. C . CH . Ph Ph . C Ph (I) CH3 H A CH3 (III) (II) Only (III) has H in conjugation with free radical 27. The reaction CH3 CH3 CH3–C–ONa+CH3CH2Cl CH3 AgNO3 ® no ppt ëéCo(NH3 )3 Cl3 ûù ¾¾¾¾ 29. A mixture of gases contains H 2 and O2 gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture ? (1) 4 : 1 (2) 16 : 1 (3) 2 : 1 (4) 1 : 4 Ans. (1) Sol. CH3–C–O–CH2–CH3 –NaCl w H2 w O2 = nH 1 1/ 2 4 Þ 2 = = 4 n O2 4 / 32 1 Which of the following processes does not involve oxidation of iron ? (1) Decolourization of blue CuSO4 solutution by iron (2) Formation of Fe(CO)5 from Fe (3) Liberation of H2 from steam by iron at high temperature (4) Rusting of iron sheets Ans. (2) LL CH3 CoCl 3 .3NH 3 Þ éëCo ( NH 3 )3 Cl3 ùû 30. Hyperconjugation occurs In :(1) II only (2) III only (3) I and III (4) I only Ans. (2) H3C Sol. EN A device that converts energy of combustion of fuels like hydrogen and methane, directly into electrical energy is known as :(1) Electrolytic cell (2) Dynamo (3) Ni-Cd cell (4) Fuel Cell Ans. (4) Sol. A device that converts energy of combustion of fuels, directly into electrical energy is known as fuel cell. 26. Consider the following compounds Sol. Given reaction is an important laboratory method for the preparation of symmetrical and unsymmetrical ethers. In this method, an alkyl halide is allowed to react with sodium alkoxide. 28. Cobalt (III) chloride forms several octahedral complexes with ammonia. Which of the following will not give test of chloride ions with silver nitrate at 25ºC ? (1) CoCl3·4NH3 (2) CoCl3·5NH3 (3) CoCl3·6NH3 (4) CoCl3·3NH3 Ans. (4) CH3 is called :(1) Williamson continuous etherification process (2) Etard reaction (3) Gatterman - Koch reaction (4) Williamson Synthesis Ans. (4) Sol. Fe0 + 5CO ® [ Fe0 ( CO )5 ] No change in the oxidation state of iron Because of lanthanoid contraction, which of the following pairs of elements have nearly same atomic radii ? (Nubmers in the parenthesis are atomic numbers). (1) Zr (40) and Nb (41) (2) Zr (40) and Hf (72) (3) Zr (40) and Ta (73) (4) Ti (22) and Zr (40) Ans. (2) Sol. Due to lanthanoid contraction atomic radii of Zr and Hf is almost similar. 32. Which of the following statements is correct for a reversible process in a state of equilibrium ? (1) DG = 2.30 RT log K (2) DGº = –2.30 RT log K (3) DGº = 2.30 RT log K (4) DG = –2.30 RT log K 5 31. AIPMT-2015 Ans. (2) Sol. DG0 = -2.30RT log K because at equilibrium DG =0 33. The angular momentum of electron in 'd' orbital is equal to :- 2h (1) (2) 2 3 h (3) 0 h R CH CH R + H2 (1 mole) R CH2 CH2 R + DH Sol. 6h (4) The enthalpy of the hydrogenation of these compounds will be in the order as :(1) III > II > I (2) II > III > I (3) II > I > III (4) I > II > III Ans. (1) Ans. (4) Sol. Orbital angular momentum = for d-orbital l=2 l ( l + 1).h so orbital angular momentum = 2 ( 2 + 1)h = 6h 34. 37. 1 stability of alkene The enolic form of ethyl acetoacetate as below has:- H3 C H C C C O H 3C EN The boiling point of 0.2 mol kg–1 solution of X in water is greater than equimolal solution of Y in water. Which one of the following statements is true in this case ? (1) Molecular mass of X is greater than the molecular mass of Y. (2) Molecular mass of X is less than the molecular mass of Y. (3) Y is undergoing dissociation in water while X undergoes no change. (4) X is undergoing dissociation is water. Ans. (4) enthalpy of hydrogenation µ OH same solvent so, Kb is same m is same (given) A 38. so, x is undergoing dissociation in water. 35. The function of "Sodium pump" is a biological process operating in each and every cell of all animals. Which of the following biologically important ions is also a consituent of this pump :(1) Mg2+ (2) K+ (3) Fe2+ (4) Ca2+ Ans. (2) Sol. K+ ion is a constituent of sodium pump 36. Given :CH H 3C CH (I) 6 3 3 CH H 3C CH (II) 3 2 CH H 2C CH (III) 2 2 O OC2H5 H Sol. H ix × k b × m > i y × k b × m Þ i x > i y H2 C C O OC2H5 (1) 16 sigma bonds and 1 pi - bond (2) 9 sigma bonds and 2 pi - bonds (3) 9 sigma bonds and 1 pi - bond (4) 18 sigma bonds and 2 pi - bonds Ans. (4) LL ( DTb )x > ( DTb )y Sol. C H H H C C C C O C C H H O H O H H 18 s + 2p Biodegradable polymer which can be produced from glycine and aminocaproic acid is :(1) PHBV (2) Buna - N (3) Nylon 6, 6 (4) Nylon 2- nylon 6 Ans. (4) Sol. Nylon 2-Nylon-6 is an alternating polyamide copolymer of glycine (NH2–CH2–COOH) and amino caproic acid [NH 2 –(CH 2) 5 COOH] and is biodegradable. 39. Which of the following species contains equal number of s- and p- bonds :(1) XeO4 (2) (CN)2 (3) CH2(CN)2 (4) HCO3– Ans. (1) CODE-F Ans. (3) O Sol. Sol. H C 3 Xe O 41. Ans. Sol. 43. number of s bonds = 4 number of p bonds = 4 Which of these statements about [Co(CN)6]3– is true:(1) [Co(CN)6]3– has four unpaired electrons and will be in a low-spin configuration. (2) [Co(CN)6]3– has four unpaired electrons and will be in a high spin configuration. (3) [Co(CN)6]3– has no unpaired electrons and will be in a high-spin configurtion. (4) [Co(CN)6]3– has no unpaired electrons and will be in a low-spin configuration. (4) [Co(CN)6]–3 Co+3 = 3d6 4s0 4p0 Q in presence of strong field ligand, pairing of electrons occurs so in this complex no unpaired electron is present and it is low spin complex. Which one is not equal to zero for an ideal solution:(1) DSmix (2) DVmix (3) DP = Pobserved - PRaoult (4) DHmix (1) For an ideal solution DSmix > 0 Which property of colloidal solution is independent of charge on the colloidal particles :(1) Electrophoresis (2) Electro-osmosis (3) Tyndall effect (4) Coagulation (3) Tyndall effect is an optical property, so it is independent of charge. Given :- OH O CH3 CH3 CH3 CH3 H OH O H CH3 CH3 Sol. OH 45. 0.693 for first order t1/2 is independent of K concentration A single compound of the structure :CH3 CH3 t1/2 = OHC C C H C C O H2 H2 is obtainable from ozonolysis of which of the following cyclic compounds ? (1) CH3 CH3 O (II) O (III) CH3 CH3 Which of the given compounds can exhibit tautomerism? (1) I and III (2) II and III (3) I, II and III (4) I and II CH3 When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is :(1) First (2) Second (3) More than zero but less than first (4) Zero Ans. (1) H3C H3C CH3 CH3 O (I) CH3 O 44. A Ans. Sol. 42. H EN Ans. Sol. CH3 O LL 40. O H3C CH3 (2) H3C CH3 (3) CH3 CH3 H3C (4) CH3 Ans. (4) Sol. H3C CH3 O3 Zn+H2 O H3 C O C OHC CH3 7 AIPMT-2015 46. Which of the following endoparasites of humans does show viviparity ? (1) Enterobius vermicularis (2) Trichinella spiralis (3) Ascaris lumbricoides (4) Ancylostoma duodenale Ans. (2) 47. Cryopreservation of gametes of threatened species in viable and fertile condition can be referred to as:(1) Advanced ex-situ conservation of biodiversity (2) In situ conservation by sacred groves (3) In situ cryo-conservation of biodiversity (4) In situ conservation of biodiversity Ans. (1) 48. Which one one of the following matches is correct ? (1) Alternaria Sexual reproduction absent (2) Mucor Reproduction Ascomycetes by Conjugation (3) Agaricus Parasitic fungus Ans. 52. Ans. 53. Basidiomycetes Basidiomycetes A Ans. (1) 49. Minerals known to be required in large amounts for plant growth include :(1) calcium, magnesium, manganese, copper (2) potassium, phosphorus, selenium, boron Ans. 54. Ans. 55. Ans. 56. (3) magnesium, sulphur, iron, zinc (4) phosphorus, potassium, sulphur, calcium Ans. (4) 50. Which of the following enhances or induces fusion of protoplasts ? Ans. 57. (1) Polyethylene glycol and sodium nitrate (2) IAA and kinetin (3) IAA and gibberellins (4) Sodium chloride and potassium chloride Ans. (1) 8 Which of these is not an important component of initiation of parturition in humans ? (1) Synthesis of prostaglandins (2) Release of oxytocin (3) Release of prolactin (4) Increase in estrogen and progesterone ratio (3) In which of the following gametophyte is not independent free living ? (2) Pteris (1) Marchantia (3) Pinus (4) Funaria (3) Which of the following is not a sexually transmitted disease ? (1) Acquired Immuno Deficiency Syndrome (AIDS) (2) Trichomoniasis (3) Encephalitis (4) Syphilis (3) Leaves become modified into spines in :(1) Pea (2) Onion (3) Silk Cotton (4) Opuntia (4) Which one gives the most valid and recent explanation for stomatal movements ? (1) Potassium influx and efflux (2) Starch hydrolysis (3) Guard cell photosynthesis (4) Transpiration (1) Which of the following had the smallest brain capacity ? (1) Homo sapiens (2) Homo neanderthalensis (3) Homo habilis (4) Homo erectus (3) High value of BOD (Biochemical Oxygen Demand) indicates that :(1) Water is highly polluted (2) Water is less polluted (3) Consumption of organic matter in the water is higher by the microbes (4) Water is pure (1) EN Deuteromycetes LL (4) Phytophthora Aseptate mycelium 51. Ans. CODE-F 58. 65. Å Ans. 60. Ans. 61. Ans. 62. A Ans. 63. Ans. 64. Ans. 67. Ans. 68. Ans. 69. LL Ans. 59. 66. The crops engineered for glyphosate are resistant/ tolerant to :(1) Bacteria (2) Insects (3) Herbicides (4) Fungi (3) Which of the following statements is not correct? (1) Goblet cells are present in the mucosa of intestine and secrete mucus (2) Oxyntic cells are present in the mucosa of stomach and secrete HCl. (3) Acini are present in the pancreas and secrete carboxypeptidase (4) Brunner's glands are present in the submucosa of stomach and secrete pepsinogen (4) In sea urchin DNA, which is double stranded, 17% of the bases were shown to be cytosine. The percentages of the other three bases expected to be present in this DNA are :(1) G 17%, A 16.5%, T 32.5% (2) G 17%, A 33%, T 33% (3) G 8.5%, A 50%, T 24.5% (4) G 34%, A 24.5%, T 24.5% (2) In Bt cotton, the Bt toxin present in plant tissue as pro-toxin is converted into active toxin due to :(1) Acidic pH of the insect gut (2) Action of gut micro-organisms (3) Presence of conversion factors in insect gut (4) Alkaline pH of the insect gut (4) Cytochromes are found in :(1) Outer wall of mitochondria (2) Cristae of mitochondria (3) Lysosomes (4) Matrix of mitochondria (2) Read the following five statements (A to E) and select the option with all correct statements :(A) Mosses and Lichens are the first organisms to colonise a bare rock. (B) Selaginella is a homosporous pteridophyte (C) Coralloid roots in Cycas have VAM (D) Main plant body in bryophytes is gametophytic, whereas in pteridophytes it is sporophytic (E) In gymnosperms, male and female gametophytes are present within sporangia located on sporophyte (1) (B), (C) and (D) (2) (A), (D) and (E) (3) (B), (C) and (E) (4) (A), (C) and (D) (2) 9 EN Ans. Sliding filament theory can be best explained as :(1) Actin and Myosin filaments shorten and slide pass each other (2) Actin and Myosin filaments do not shorten but rather slide pass each other (3) When myofilaments slide pass each other, Myosin filaments shorten while Actin filaments do not shorten (4) When myofilaments slide pass each other Actin filaments shorten while Myosin filament do not shorten (2) A gymnast is able to balance his body upside down even in the total darkness because of :(1) Vestibular apparatus (2) Tectorial membrane (3) Organ of corti (4) Cochlea (1) A man with blood group 'A' marries a woman with blood group 'B'. What are all the possible blood groups of their offsprings ? (1) A,B and AB only (2) A,B,AB and O (3) O only (4) A and B only (2) Typical growth curve in plants is :(1) Linear (2) Stair-steps shaped (3) Parabolic (4) Sigmoid (4) The UN Conference of Parties on climate change in the year 2011 was held in :(1) South Africa (2) Peru (3) Qatar (4) Poland (1) A technique of micropropagation is :(1) Somatic embryogenesis (2) Protoplast fusion (3) Embryo rescue (4) Somatic hybridization (1) How many pairs of contrasting characters in pea plants were studied by Mendel in his experiments ? (1) Six (2) Eight (3) Seven (4) Five (3) Ans. 70. Ans. 71. K(5) C(5) A5 G(2) is the floral formula of :- (1) Sesbania (3) Brassica (2) Petunia (4) Allium Ans. (2) Ans. AIPMT-2015 Which one of the following is correct ? (1) Serum = Blood + Fibrinogen (2) Lymph = Plasma + RBC + WBC (3) Blood = Plasma + RBC + WBC (4) Plasma = Blood – Lymphocytes Ans. (3) 73. The movement of a gene from one linkage group to another is called :(1) Duplication (2) Translocation (3) Crossing over (4) Inversion Ans. (2) 74. Which body of the Government of India regulates GM research and safety of introducing GM organisms for public services ? (1) Indian Council of Agricultural Research (2) Genetic Engineering Approval Committee (3) Research Committee on Genetic Manipulation (4) Bio-safety committee Ans. (2) 75. Rachel Carson's famous book "Silent Spring" is related to :(1) Noise pollution (2) Population explosion (3) Ecosystem management Ans. 80. Ans. 81. Ans. 82. Ans. 83. Ans. 84. LL (4) Pesticide pollution Ans. (4) 76. Gastric juice of infants contains :- 79. (1) nuclease, pepsinogen, lipase (2) pepsinogen, lipase, rennin (3) amylase, rennin, pepsinogen A (4) maltase, pepsinogen, rennin Ans. (2) 77. Which of the following is not one of the prime health risks associated with greater UV radiation through the atmosphere due to depletion of stratospheric ozone ? (1) Reduced Immune System (2) Damage to eyes (3) Increased liver cancer Ans. 85. Ans. 86. (4) Increased skin cancer Ans. (3) 78. Capacitation refers to changes in the :(1) Ovum before fertilization (2) Ovum after fertilization (3) Sperm after fertilization (4) Sperm before fertilization Ans. (4) 10 Most animals are tree dwellers in a:(1) Thorn woodland (2) Temperate deciduous forest (3) Tropical rain forest (4) Coniferous forest (3) True nucleus is absent in :(1) Mucor (2) Vaucheria (3) Volvox (4) Anabaena (4) Glenoid cavity articulates :(1) Scapula with acromion (2) Clavicle with scapula (3) Humerus with scapula (4) Clavicle with acromion (3) Transmission tissue is characteristic feature of :(1) Solid style (2) Dry stigma (3) Wet stigma (4) Hollow style (1) DNA is not present in :(1) Ribosomes (2) Nucleus (3) Mitochondria (4) Chloroplast (1) Gene regulation governing lactose operon of E.coli that involves the lac I gene product is : (1) Negative and inducible because repressor protein prevents transcription (2) Negative and repressible because repressor protein prevents transcription (3) Feedback inhibition because excess of b-galactosidase can switch off trascription (4) Positive and inducible because it can be induced by lactose (1) Which of the following does not favour the formation of large quantities of dilute urine ? (1) Caffeine (2) Renin (3) Atrial-natriuretic factor (4) Alcohol (2) What causes a green plant exposed to the light on only one side, to bend toward the source of light as it grows ? (1) Green plants seek light because they are phototropic (2) Light stimulates plant cells on the lighted side to grow faster (3) Auxin accumulates on the shaded side, stimulating greater cell elongation there. (4) Green plants need light to perform photosynthesis (3) EN 72. Ans. CODE-F 87. 93. Nuclear envelope is a derivative of :(1) Membrane of Golgi complex (2) Microtubules (3) Rough endoplasmic reticulum (4) Smooth endoplasmic reticulum Ans. (3) 88. Select the correct option :I (1) Leucocytes (2) Helper T- Lymphocytes (3) Thrombocytes (4) B- Lymphocytes Ans. (2) 94. Hysteresctomy is surgical removal of : II (a) Synapsis aligns homologous chromosomes (i) Anaphase-II (b) Synthesis of RNA and protein (ii) Zygotene (c) Action of enzyme recombinase (iii) G2-phase (d) Centromeres do not separate but chromatids move towards opposite poles (iv) Ans. 91. Ans. 92. Ans. Pachytene (a) (b) (c) (d) (1) (ii) (iii) (v) (iv) (2) (i) (ii) (v) (iv) (3) (ii) (iii) (iv) (v) (4) (ii) (i) (iii) (iv) (1) Keel is the characteristic feature of flower of :(1) Indigofera (2) Aloe (3) Tomato (4) Tulip (1) Perigynous flowers are found in :(1) Cucumber (2) China rose (3) Rose (4) Guava (3) A chemical signal that has both endocrine and neural roles is ? (1) Calcitonin (2) Epinephrine (3) Cortisol (4) Melatonin (2) In which of the following both pairs have correct combination :(1) In situ conservation : Cryopreservation Ex situ conservation : Wildlife Sanctuary (2) In situ conservation : Seed Bank Ex situ conservation : National Park (3) In situ conservation : Tissue culture Ex situ conservation : Sacred groves (4) In situ conservation : National Park Ex situ conservation : Botanical Garden (4) A Ans. 90. (4) Uterus Ans. (4) 95. Removal of proximal convoluted tubule from the nephron will result in: (1) More concentrated urine (2) No change in quality and quantity of urine (3) No urine formation (4) More diluted urine Ans. (4) 96. A major characteristic of the monocot root is the presence of : (1) Scattered vascular bundles LL Ans. 89. Anaphase-I (1) Prostate gland (2) Vas-deference (3) Mammary glands EN (v) HIV that causes AIDS, first starts destroying: (2) Vasculature without cambium (3) Cambium sandwiched between phloem and xylem along the radius (4) Open vascular bundles Ans. (2) 97. Which of the following characteristics is mainly responsible for diversification of insects on land ? (1) Bilateral symmetry (2) Exoskeleton (3) Eyes (4) Segmentation Ans. (2) 98. Which of the following cells during gametogenesis is normally dipoid? (1) Spermatid (2) Spermatogonia (3) Secondary polar body (4) Primary polar body Ans. (2) 99. The structures that are formed by stacking of organized flattened membranous sacs in the chloroplasts are : (1) Grana (2) Stroma lamellae (3) Stroma (4) Cristae Ans. (1) 11 AIPMT-2015 107. Erythropoiesis starts in : (1) Liver (2) Spleen (3) Red bone marrow (4) Kidney Ans. (3) 108. Which is the most common mechanism of genetic variation in the population of sexually reproducing organism? (1) Chromosomal aberrations (2) Genetic drift (3) Recombination (4) Transduction Ans. (3) 109. Blood pressure in the mammalian aorta is maximum during : EN 100. The chromosomes in which centromere is situated close to one end are: (1) Acrocentric (2) Telocentric (3) Sub-metacentric (4) Metacentric Ans. (1) 101. In a ring girdled plant: (1) The root dies first (2) The shoot and root die together (3) Neither root nor shoot will die (4) The shoot dies first Ans. (1) 102. Vertical distribution of different species occupying different levels in a biotic community is known as: (1) Stratification (2) Zonation (3) Pyramid (4) Divergence Ans. (1) 103. Multiple alleles are present : (1) At different loci on the same chromosome (2) At the same locus of the chromosome (3) On non-sister chromatids (4) On different chromosomes Ans. (2) 104. The mass of living material at a trophic level at a particular time is called : (1) Standing state (2) Net primary productivity (3) Standing crop (4) Gross primary productivity Ans. (3) (1) Diastole of the right ventricle (2) Systole of the left ventricle (3) Diastole of the right atrium (4) Systole of the left atrium Ans. (2) A LL 110. When you hold your breath, which of the following gas changes in blood would first lead to the urge to breathe? 105. Which of the following animals is not viviparous? (1) Elephant (2) Platypus (3) Whale (4) Flying fox (Bat) Ans. (2) 106. In an ecosystem the rate of production of organic matter during photosynthesis is termed as: (1) Gross primary productivity (2) Secondary productivity (3) Net productivity (4) Net primary productivity Ans. (1) 12 (1) rising CO2 concentration (2) falling CO2 concentration (3) rising CO2 and falling O2 concentration (4) falling O2 concentration Ans. (1) 111. Vascular bundles in monocotyledons are considered closed because: (1) Cambium is absent (2) There are no vessels with perforations (3) Xylem is surrounded all around by phloem (4) A bundle sheath surrounds each bundle Ans. (1) 112. Male gemetes are flagellated in : (1) Anabaena (2) Ectocarpus (3) Spirogyra (4) Polysiphonia Ans. (2) CODE-F 113. Which one of the following may require pollinators, but is genetically similar to autogamy ? (1) Xenogamy (2) Apogamy (3) Cleistogamy (4) Geitonogamy Ans. (4) 114. In ginger vegetative propagation occurs through: (1) Offsets (2) Bulbils (3) Runners (4) Rhizome Ans. (4) 115. Which one of the following is not an inclusion body 120. Which of the following represents the correct combination without any exception? Characteristics (1) Mouth ventral, gills without operculum; skin with placoid scales; persistent notochord Chondrichthyes (2) Sucking and circular mouth; jaws absent, integument without scales; paired appendages Cyclostomata (3) Body covered with feathers; skin moist and glandular; fore-limbs form wings; lungs with air sacs Aves (4) Mammary gland; hair on body; pinnae; two pairs of Limbs Mammalia found in prokaryotes ? (1) Cyanophycean granule (2) Glycogen granule (3) Polysome (4) Phosphate granule Ans. (3) Ans. (1) 121. Which one of the following statements in incorrect? (1) In competitive inhibition, the inhibitor molecule is not chemically changed by the enzyme. EN 116. A somatic cell that has just completed the S phase (2) The competitive inhibitor does not affect the rate of breakdown of the enzyme-substrate complex. of its cell cycle, as compared to gamete of the same species, has : (1) same number of chromosomes but twice the amount of DNA (3) The presence of the competitive inhibitor decreases the Km of the enzyme for the substrate. (2) twice the number of chromosomes and four times the amount of DNA LL (3) four times the number of chromosomes and twice the amount of DNA (4) twice the number of chromosomes and twice the amount of DNA Ans. (2) 117. Alleles are : (1) true breeding homozygotes (2) different molecular forms of a gene (3) heterozygotes (4) different phenotype Ans. (2) 118. Select the correct matching in the following pairs: (1) Smooth ER – Synthesis of lipids (2) Rough ER– Synthesis of glycogen (3) Rough ER – Oxidation of fatty acids (4) Smooth ER – Oxidation of phospholipids Ans. (1) 119. The terga, sterna and pleura of cockroach body are joined by : (1) Muscular tissue (2) Arthrodial membrane (3) Cartilage (4) Cementing glue Ans. (2) A Class (4) A competitive inhibitor reacts reversibly withthe enzyme to form an enzyme- inhibitor complex. Ans. (3) 122. Which of the following regions of the brain is incorrectly paired with its function? (1) Cerebellum- language comprehension (2) Corpus callosum-communication between the left and right cerebral cortices (3) Cerebrum- calculation and contemplation (4) Medulla oblongata - homeostatic control Ans. (1) 123. Which one of the following statements is not true? (1) Pollen grains of some plants cause severe allergies and bronchial afflictions in some people (2) The flowers pollinated by flies and bats secrete foul odour to attract them (3) Honey is made by bees by digesting - pollen collected from flowers (4) Pollen grains are rich in nutrients, and they are used in the form of tablets and syrups Ans. (3) 13 AIPMT-2015 131. The following graph depicts changes in two populations (A and B) of herbivores in a grassy field A possible reason for these changes is that: (4) erythrocytes; mucosa and submucosa of colon (4) Fucus spp. A Time (1) Population B competed more successfully for food than population A (2) Population A produced more offspring than population B (3) Population A consumed the members of population B (4) Both plant populations in this habitat decreased Ans. (1) 132. Match each disease with its correct type of vaccine: EN Ans. (4) 125. Which of the following viruses is not transferred through semen of an infected male? (1) Human immunodeficiency virus (2) Chikungunya virus (3) Ebola virus (4) Hepatitis B virus Ans. (2) 126. A population will not exist in Hardy - Weinberg equilibrium if : (1) There are no mutations (2) There is no migration (3) The population is large (4) Individuals mate selectively Ans. (4) 127. The guts of cow and buffalo possess: (1) Chlorella spp. (2) Methanogens (3) Cyanobacteria A LL Ans. (2) 128. The hilum is a scar on the : (1) Fruit, where it was attached to pedicel (2) Fruit, where style was present (3) Seed, where micropyle was present (4) Seed, where funicle was attached Ans. (4) 129. Secondary Succession takes place on/in : (1) Degraded forest (2) Newly created pond (3) Newly cooled lava (4) Bare rock Ans. (1) 130. Which one of the following statements is wrong? (1) Agar - agar is obtained from Gelidium and Gracilaria (2) Chlorella and Spirulina are used as space food (3) Mannitol is stored food in Rhodophyceae (4) Algin and carragen are products of algae Ans. (3) 14 B Number of Organisms 124. The active from of Entamoeba histolytica feeds upon: (1) mucosa and submucosa of colon only (2) food in intestine (3) blood only (a) tuberculosis (i) harmless virus (b) whooping cough (ii) inactivated toxin (c) diphtheria (iii) killed bacteria (d) polio (iv) harmless bacteria (a) (b) (c) (d) (1) (iii) (2) (iv) (ii) (iii) (iv) (ii) (i) (i) (3) (i) (ii) (iv) (iii) (4) (ii) (i) (iii) (iv) Ans. (2) 133. Which of the following are the important floral rewards to the animal pollinators? (1) Nectar and pollen grains (2) Floral fragrance and calcium crystals (3) Protein pellicle and stigmatic exudates (4) Colour and large size flower Ans. (1) 134. An abnormal human baby with 'XXX' sex chromosomes was born due to : (1) formation of abnormal ova in the mother (2) fusion of two ova and one sperm (3) fusion of two sperms and one ovum (4) formation of abnormal sperms in the father Ans. (1) 135. Transpiration and root pressure cause water to rise in plants by : (1) Pulling and pushing it, respectively (2) Pushing it upward (3) Pushing and pulling it, respectively (4) Pushing it upward Ans. (1) CODE-F 136. An electron moving in a circular orbit of radius r makes n rotations per second. The magnetic field produced at the centre has magnitude : (1) Zero m 0n 2e r (2) (3) m0ne 2r (4) 138. When tw o dispalcements represen ted by y1 = asin(wt) and y2 = b cos(wt) are superimposed the motion is : m0ne 2pr (1) simple harmonic with amplitude Ans. (3) Sol. Magnetic field due to a circular loop B= m0 NI 2r (2) simple harmonic with amplitude (3) simple harmonic with amplitude Where N ® no. of loops I= q e = = ne T 1/n B= m0 ne (Here N = 1 as e– makes only one loop) 2r & y2 = b cos wt = b sin (wt + EN B Amplitude A = so A = LL P(in kPa) 2 4 6 3 V(in m ) A The change in internal energy of the gas during the transition is : (1) –20 kJ (2) 20 J (3) –12 kJ (4) 20 kJ Ans. (1) & T= Sol. DU = n CV DT so DT = T2 - T1 = so PV nR P2 V2 - P1 V1 nR nR æ P2 V2 - P1 V1 ö P2 V2 - P1 V1 DU = ÷= g - 1 çè g -1 nR ø Þ DU = -8 ´ 10 2/5 Hence option (1) =–20 kJ p ) 2 A12 + A 22 + 2A1 A 2 cos f p 2 a2 + b2 Hence option (2) 139. A particle of unit mass undergoes one-dimensional motion such that its velocity varies according to v(x) = bx–2n where b and n are constants and x is the position of the particle. The acceleraion of the particle as a function of x, is given by : (1) –2nb2x–4n–1 (2) –2b2x–2n+1 (3) –2nb2e–4n+1 (4) –2nb2x–2n–1 Ans. (1) Sol. v = b x–2n so dv = – 2nb x–2n–1 dx Now a = v 3 (a + b) 2 since the frequencies for both SHM are same, resultant motion will be SHM. Now here A1 = a, A2 = b & f = A a2 + b2 (4) not a simple harmonic Ans. (2) Sol. y1 = a sin wt hence option (3) 137. One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in the figure, 5 a b dv = (bx–2n) (–2nb x–2n–1) dx Þ a = –2nb2 x–4n–1 Hence option (1) 15 AIPMT-2015 140. If radius of the 125 53 the radius of (1) 27 13 Al nucleus is taken to be RAl then = 2D Te nucleus is nearly : 5 R Al 3 (2) 1/3 æ 13 ö (3) ç ÷ è 53 ø Sol. Linear width of central maxima = D (2q) = 2Dq l a 3 R Al 5 1/3 æ 53 ö (4) ç ÷ è 13 ø R Al R Al q q Ans. (1) Sol. R µ A1/3 D 1/ 3 R Al æ 27 ö =ç ÷ R Te è 125 ø Þ RTee = 5 R 3 Al Hence Option (4) 143. Across a metallic conductor of non-uniform cross section a constant potential difference is applied. The quantity which remains constant along the conductor is : (1) current (2) drift velocity (3) electric field (4) current density Ans. (1) Sol. Metallic conductor can be considered as the combination of various conductors connected in series combination. And in series combination the current always remains constant. LL EN hence option (1) 141. In a double slit experiment, the two slits are 1 mm apart and the screen is placed 1 m away. A monochromatic light of wavelength 500 nm is used. What will be the width of each slit for obtaining ten maxima of double slit within the central maxima of single slit pattern ? (1) 0.1 mm (2) 0.5 mm (3) 0.02 mm (4) 0.2 mm Ans. (4) Sol. Angular width of central maxima in double slit lD b l experiment = = d = D D d A Angular width of central maxima in single slit experiment = 2l d' According to the question 10l 2l = d d' Þ d' = 0.2 d = 0.2 mm hence option (4) 142. For a parallel beam of monochromatic light of wavelength 'l', diffraction is produced by a single slit whose width 'a' is of the order of the wavelength of the light. If 'D' is the distance of the screen from the slit, the width of the central maxima will be : (1) Ans. (4) 16 Dl a (2) Da l (3) 2Da l (4) 2Dl a Hence option (1) 144. On observing light from three different stars P, Q and R, it was found that intensity of violet color is maximum in the spectrum of P, the intensity of green colour is maximum in the spectrum of R and the intensity or red colour is maximum in the spectrum of Q. If TP, TQ and TR are the respective absolute temperatures of P, Q and R, then it can be concluded from the above observation that : (1) TP > TR > TQ (2) TP < TR < TQ (3) TP < TQ < TR (4) TP > TQ > TR Ans. (1) Sol. From Wein's displacement law 1 lm µ T Now from sequence ‘VIBGYOR’ (lm)P < (lm)R < (lm)Q So TP > TR > TQ Hence option (1) CODE-F 145. A potentiometer wire has length 4 m and resistance 8W. The resistance that must be connected in series with the wire and an accumulator of e.m.f. 2V, so as to get a potential gradient 1 mV per cm on the wire is : (1) 40 W (2) 44 W (3) 48 W 147. A wire carrying current I has the shape as shown in adjoining figure. Linear parts of the wire are very long and parallel to X-axis while semicircular portion of radius R is lying in Y-Z plane. Magnetic field at point O is : (4) 32 W Z Ans. (4) Sol. Potential gradient = 1mV = 10–3 V/cm = 10–1V/m cm I R I 2 I= 8+R I X Potential drop across the potentiometer wire Þ R = 32W Hence option (4) A 146. Consider 3 rd orbit of He + (Helium), using non-relativistic approach, the speed of electron in this orbit will be [given K = 9 × 109 constant, Z = 2 and h (Planck's Constant) = 6.6 × 10–34 J s] 8 (3) 3.0 × 10 m/s (4) 2.92 × 106 m/s Ans. (1) Sol. For H-like atoms Z × 2.188 × 106 m/s n here Z = 2, n = 3 6 n = 1.46 × 10 m/s Hence option (1) r µ0 I ( ˆ pi + 2kˆ ) 4p R r µ0 I ( ˆ p i - 2kˆ ) 4p R r µ0 I ( ˆ p i + 2kˆ ) 4p R (3) B = LL 4 = = 0.1 8+R (2) 0.73 × 106 m/s µ0 I ( ˆ pi - 2kˆ ) 4p R (2) B = - æ 16 ö 1 Potential gradient = ç ÷ ´ V/m è8+Rø 4 (1) 1.46 × 106 m/s r (1) B = - EN 8´2 16 = = 8+R 8+R n= Y O Let the resistance to be connected is R then (4) B = Ans. (2) Sol. 'B' due to segment '1' B1 = m0 I [sin 90° + sin q] (– k̂ ) 4 pR 2 m0 I B1 = (– k̂ ) = B3 4 pR B due to segment '2' B2 = I 1 3 I m0 I ( -ˆi) 4R r r r r so 'B' at center Bc = B1 + B2 + B3 r Þ BC = -m 0 I æ -m 0 I 2kˆ ö ˆ çè î + ÷ø = ( pˆi + 2k) 4R 4 pR p Hence option (2) 17 AIPMT-2015 148. Which of the following figures represent the variation of particle momentum and the associated de-Broglie wavelength ? p p (1) (2) l l p pipe = Now (4) l l hc 1 Þ P µ (Rectangular hyperbola) l l hence option (1) (1) The energy stored in the capacitor decreases K times. A 1 æ1 ö CV 2 ç – 1 ÷ . 2 èK ø (3) The charge on the capacitor is not conserved. (4) The potential difference between the plates decreases K times. Ans. (3) Sol. Once the capacitor is charged, its charge will be constant Q = CV When dielectric slab is inserted C'New = KC E= 1 Q2 Þ ENew = E K initial 2C Q 1 V= so Vnew = V C K Hence option (3) 18 v 3v Þ l0 = 6lc = 6(20 cm) = 120 cm = 4l c 2l 0 Hence option (2) 151. The refracting angle of a prism is A, and refractive index of the material of the prism is cot(A/2). The angle of minimum deviation is :(1) 180° – 2A (2) 90° – A (3) 180° + 2A (4) 180° – 3A Ans. (1) æd +Aö sin ç m ÷ è 2 ø Sol. m = æAö sin ç ÷ è2ø Q m = cot (A/2) LL 149. A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect ? (2) The change in energy stored is 3v 2l 0 EN Ans. (1) v 4l c 2nd overtone frequency of open organ pipe = p (3) Sol. P = 150. The fundamental frequency of a closed organ pipe of length 20 cm is equal to the second overtone of an organ pipe open at both the ends. The length of organ pipe open at both the ends is :(1) 100 cm (2) 120 cm (3) 140 cm (4) 80 cm Ans. (2) Sol. Fun damental fre quen cy o f closed org an æd +Aö sin ç m ÷ è 2 ø \ cot (A/2) = æAö sin ç ÷ è2ø d +Aö Þ cos (A/2) = sin æç m ÷ è 2 ø dm + A 2 Þ dm = 180° – 2A hence option (1) 152. Which logic gate is represented by the following combination of logic gates ? Þ 90° – A/2 = A Y1 Y B (1) NAND (3) NOR Ans. (2) Y2 (2) AND (4) OR CODE-F Sol. y1 = A , y2 = B , y = y 1 + y 2 = A + B (using De-morgan's theorem) y=A·B Hence this logic gate represents AND gate. Hence option (2) 1 as 153. A Carnot engine, having an efficiency of h = 10 heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is :(1) 99 J (2) 90 J (3) 1 J (4) 100 J Ans. (2) Sol. For Engine & refrigerators operating between two same temperatures 1 1+ b Þ (1) E/C E/C 2E C2 Sol. l 6 (4) 6 l Ans. (1) hc hc Sol. eVS = E – f Þ VS = le – l e 0 here hc hc 3V0 = le – l e 0 hc hc and V0 = 2le – l e 0 equation (1) – 3 × equation (2) hc 2hc + Þ 0=– 2le l 0e Þ l0 = 4l Hence option (1) (4) E C E C So momentum transferred to the surface 2E = pƒ – pi = C Hence option (1) Momentum of light p = attached to a string which passes through a smooth hole in the plane as shown. LL A (3) E C2 plane with velocity v0 at a radius R0. The mass is Hence option (2) 154. A certain metallic surface is illuminated with monochromatic light of wavelength, l. The stopping potential for photo-electric current for this light is 3V0. if the same surface is illuminated with light of wavelength 2l, the stopping potential is V0. The threshold wavelength for this surface for photoelectric effect is :l 4 (3) Ans. (1) Q2 (From the principle of refrigerator) W Q 9= 2 Þ Q2 = 90 Joule 10 (2) (2) 156. A mass m moves in a circle on a smooth horizontal 1 1 = Þb=9 10 1 + b b= (1) 4 l 2E C EN h= 155. A radiation of energy ‘E’ falls normally on a perfectly reflecting surface. The momentum transferred to the surface is (C = Velocity of light) :- ...(1) ...(2) v0 m R0 The tension in the string is increased gradually and R finally m moves in a circle of radius 0 . The final 2 value of the kinetic energy is :(1) 1 mv 20 4 (2) 2mv 20 (3) 1 mv 20 2 (4) mv 20 Ans. (2) Sol. Angular momentum remains Constant because of the torque of tension is zero. Þ Li = Lf Þ mv0R = mv R 2 Þ v = 2v0 KEf = 1 2 m ( 2v0 ) = 2mv 02 2 hence option (2) 19 AIPMT-2015 157. Two identical thin plano-convex glass lenses (refractive index 1.5) each having radius of curvature of 20 cm are placed with their convex surfaces in contact at the centre. The intervening space is filled with oil of refractive index 1.7. The focal length of the combination is :(1) –25 cm (2) –50 cm (3) 50 cm (4) –20 cm Ans. (2) a Sol. m1 A mk T mk m1g T m2 B a m2g n2 = 1.7 For the motion of both blocks m2g – T = m2a T – mk m1g = m1a Sol. n1 = 1.5 Þ a= For the block of mass 'm2' From lens maker's formula é m - mk m1 ù m2 g - T = m2 ê 2 úg ë m1 + m2 û EN æ 1 1 1 ö = (m - 1) ç ÷ f R R è 1 2 ø we have é m - m k m1 ù é m1 + mk m1 ù T = m2 g - ê 2 ú m2 g = m2 g ê ú ë m1 + m2 û ë m1 + m2 û 1 æ 1 ö 1 = (1.5 - 1) ç ÷= f1 è 20 ø 40 1 æ 1 ö 1 = (1.5 - 1) ç ÷= f2 è 20 ø 40 Now 1 7 æ 2 ö = (1.7 - 1) ç = ÷ f3 è 20 ø 100 1 1 1 1 = + + f f1 f2 f3 1 1 1 7 = + f 40 40 100 Þ f = – 50 cm Hence option (2) 158. A block A of mass m1 rests on a horizontal table. A Þ Þ T= LL & (m2 - mk m1 )g m1 + m2 A light string connected to it passes over a frictionless pulley at the edge of table and from its other end another block B of mass m2 is suspended. The coefficient of kinetic friction between the block and the table is µ k. When the block A is sliding on the table, the tension in the string is :- m1m2 (1 + mk )g m 1 + m2 Hence option (2) 159. A particle is executing SHM along a straight line. Its velocities at distances x1 and x2 from the mean position are V1 and V2, respectively. Its time period is :x 22 – x12 (1) 2p V12 – V22 V12 + V22 (2) 2p x12 + x 22 V12 – V22 (3) 2p x12 – x 22 x12 + x 22 (4) 2p V12 + V22 Ans. (1) Sol. For particle undergoing SHM V = w A 2 - x2 so V1 = w A 2 - x12 solving these two equations we get V12 - V22 2p = x 22 - x12 T (1) (m2 – mk m1 )g (m1 + m2 ) (2) m1m2 (1 + m k )g (m1 + m2 ) w= (3) m1m2 (1 – m k )g (m1 + m2 ) (4) (m2 + mk m1 )g (m1 + m2 ) Þ T = 2p Ans. (2) 20 & V2 = w A 2 - x22 x 22 - x12 V12 - V22 Hence option (1) CODE-F 160. A ship A is moving Westwards with a speed of 10 km h–1 and a ship B 100 km South of A, is moving Northwards with a speed of 10 km h–1. The time after which the distance between them becomes shortest, is :(1) 5 h (2) 5 2 h (3) 10 2 h (4) 0 h Ans. (1) Sol. As we know 10 kmph B= A ph vB A = 10 2 Now P = rgh & compressibility 'K' = so r v BA = 102 + 102 = 10 2 kmph A tsn = 5 hrs. Hence option (1) 161. A rod of weight W is supported by two parallel knife edges A and B and is in equilibrium in a horizontal position. The knives are at a distance d from each other. The centre of mass of the rod is at distance x from A. The normal reaction on A is :- (3) (2) W(d – x) d (4) Ans. (3) Sol. By torque balancing about B NA(d) = W(d–x) Þ NA = Hence option (2) 163. Two particles of masses m1, m2 move with initial velociteis u1 and u2. On collision, one of the particles get excited to higher level, after abosrbing energy e. If final velocities of particles be v1 and v2 then we must have : LL 50 2 50 2 = r v BA 10 2 Wd x W(d - x) d Hence option (3) DV = rgh (K) V = 1.201 × 10–2 Time taken to reach the shortest distance between (1) 1 B = 103 × 9.8 × 2700 × 45.4 × 10–11 distance OB = 100 cos45°= 50 2 km A&B= DV P = V B km 45° B so O 10 kmph P DV V EN Sol. 100km 162. The approximate depth of an ocean is 2700 m. The compressibility of water is 45.4 × 10–11 Pa–1 and density of water is 103 kg/m3.What fractional compression of water will be obtained at the bottom of the ocean ? (1) 1.0 × 10–2 (2) 1.2 × 10–2 –2 (3) 1.4 × 10 (4) 0.8 × 10–2 Ans. (2) (1) 1 1 1 1 m 1u12 + m 2 u 22 = m 1v12 + m 2 v 22 - e 2 2 2 2 (2) 1 1 1 1 m 1u12 + m 2 u 22 - e = m 1v12 + m 2v 22 2 2 2 2 (3) 1 2 2 1 2 2 1 1 m 1 u1 + m 2 u 2 + e = m 12v12 + m 22 v 22 2 2 2 2 W(d – x) x Wx d (4) m12u1 + m22u2 – e = m12v1 + m22v2 Ans. (2) NA NB Sol. Energy will always be conserved so K. E.initial = K.E.final + Excitation energy A B x W d–x 1 1 1 1 m1u12 + m2u22 = m1v12 + m2 v 22 + e 2 2 2 2 Hence option (2) . 21 AIPMT-2015 164. Kepler's third law states that square of period of revolution (T) of a planet around the sun, is proportional to third power of average distance r between sun and planet i.e. T2 = Kr3 here K is constant. If the masses of sun and planet are M and m respectively then as per Newton's law of gravitation force of attraction between them is F = GMm , here G is gravitational constant. r2 From work energy theorem W = Kƒ – Ki Þ –25 = Kƒ – Þ Kƒ = 475 Hence option (4) 166. A wind with speed 40 m/s blows parallel to the roof of a house. The area of the roof is 250 m2. Assuming that the pressure inside the house is atmospheric pressure, the force exerted by the wind on the roof and the direction of the force will be : (rair = 1.2 kg/m3) The relation between G and K is described as : (1) GMK = 4p2 (2) K = G (4) GK = 4p2 Ans. (2) æ ç as n = è EN 2pr 2pr r = Sol. T = v GM Sol. By Bernaulli's equation 1 P + rv2 = P0 + 0 2 GM ö ÷ r ø 2p GM 1 p0 - p = rv2 2 3/2 r 2 LL 4p · r3 GM Comparing 4p 2 GM Hence option (1) 165. A block of mass 10 kg, moving in x direction with a constant speed of 10 ms–1, is subjected to a retarding force F = 0.1 x J/m during its travel from x = 20 m to 30 m. Its final KE will be : A K= (3) 2.4 × 105 N, downwards (4) 4.8 × 105 N, downwards Ans. (1) T2 = (1) 4.8 × 105 N, upwards (2) 2.4 × 105 N, upwards 1 (3) K = G T= 1 2 10(10) 2 (1) 450 J (2) 275 J (3) 250 J (4) 475 J Ans. (4) Sol. W = – ò Fdx Pin = P0 vin = 0 1 F = rv2 A 2 F = 2.4 × 105 upward Hence Option (2) 167. Two spherical bodies of mass M and 5 M and radii R and 2 R are released in free space with initial separation between their centres equal to 12 R. If they attract each other due to gravitational force only, then the distance covered by the smaller body before collision is : (1) 4.5 R (2) 7.5 R (3) 1.5 R (4) 2.5 R Ans. (2) 12R Sol. 30 W = – ò 0.1x dx Initial distance between their centers = 12 R 20 30 é x2 ù W = –0.1 ê ú ë 2 û 20 é 900 – 400 ù W = –0.1 ê úû = –25 ë 2 22 R 2R At time of collision the distance between their centers = 3R So total distance travelled by both=12R–3R = 9R CODE-F Since the bodies move under mutual forces, center of mass will remain stationary so CP = g in terms of CV 169. The ratio of the specific heats m1x1 = m2x2 degrees of freedom (n) is given by : mx = 5m(9R –x) x = 45R – 5x 6x = 45R (1) ç 1 + æ è nö ÷ 3ø (2) ç 1 + æ è 2ö ÷ nø 45 R 6 (3) ç 1 + æ è nö ÷ 2ø (4) ç 1 + æ è 1ö ÷ nø x= Ans. (2) x = 7.5R (1) P R Z æRö ÷ èZø (2) P ç æRö ÷ èZø (4) P ç (3) P Ans. (4) Sol. R V2 R Þ V2 = PR 2 n 2 P 4 6×10 Pa Resistor & Inductor circuit R L f Impedance = Z éVù P ' = V. ê ú .cos f ë Zû P' = V2 R · Z Z (From phasor diagram) P' = (PR)R Z2 2 æRö P' = ç ÷ P è Zø Hence option (4) B C (Phasor diagram) A P= \ g= 1 + Hence option (2) 170. Figure below shows two paths that may be taken by a gas to go from a state A to a state C. R Z AC source 2 n Here degree of freedom ® n LL Pure resistor circuit Sol. g = 1 + EN Hence option (2) 168. A resitance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z', the power drawn will be: XL A 2×104 Pa –3 3 2×10 m 4×10–3 m3 V In process AB, 400 J of heat is added to the system and in process BC, 100 J of heat is added to the system. The heat absorbed by the system in the process AC will be : (1) 500 J (2) 460 J (3) 300 J (4) 380 J Ans. (2) Sol. In cyclic process ABCA, DUcyclic = 0 Qcyclic = Wcyclic QAB + QBC + QCA = closed loop area. 400 + 100 + QCA = 1 × (2 × 10–3) × 4 × 104 2 400 + 100 –QAC = 40 QAC = 460 J Hence option (2) 23 AIPMT-2015 171. If energy (E), velocity (V) and time (T) are chosen as the fundamental quantities, the dimensional formula of surface tension will be : (1) [EV–1T–2] (2) [EV–2T–2] (3) [E–2V–1T–3] (4) [EV–2T–1] Ans. (2) Sol. Applying dimensional analysis a 173. Three blocks A, B and C of masses 4 kg, 2 kg and 1 kg respectively, are in contact on a frictionless surface, as shown. If a force of 14 N is applied on the 4 kg block, then the contact force between A and B is : b c SµEVT 1 0 –2 1 2 –2 a 1 0 –2 a 2a –2a 1 –1 b 1c M L T = k [M L T ] [L T ] [T ] M L T = k [M L T Comparision a =1 (1) 6 N Ans. (1) b –b c ]L T T 2a + b = 0 –2 = –2a – b + c b = –2 –2 = –2(1) + 2 + c (2) 8 N (3) 18 N Sol. Acceleration of system c = –2 So the dimensional formula for surface tension will 1 –2 –2 be [E V T ] Alternate solution : Surface energy Surface Tension = Area [E] –2 –2 [Surface tension] = = [E V T ] [V × T]2 Hence option (2) 172. If in a p-n junction, a square input signal of 10 V is applied as shown, Fnet = M total = EN 14 N 4kg (4) 2 N 14 = 2 m/s2 4 + 2 +1 2kg 1kg The contact force between 4 kg & 2 kg block will move 2 kg & 1 kg block with the same acceleration so Fcontact = (2 + 1)a = 3(2) = 6N +5V LL Hence option (1) 174. A, B and C are voltmeters of resistance R, 1.5 R RL –5V A then the output across RL will be : and 3R respectively as shown in the figure. When some potential difference is applied between X and Y, the voltmeter readings are V A, VB and VC respectively. Then : 10V (1) (2) B –5V 5V (3) (4) –10V Ans. (3) Sol. This is the circuit where P-N junction is acting as a Half-wave rectifier so the output will be 5V Hence option (3) 24 X A (1) VA ¹ VB = VC (3) VA ¹ VB ¹ VC Ans. (4) Y C (2) VA = VB ¹ VC (4) VA = VB = VC Sol. Effective resistance of B & C = (1.5R)(3R) =R 1.5R + 3R In series sequence V µ R so voltage across 'A' = voltage across B & C Now B & C are parallel so VB = VC Þ VA = VB = VC Hence option (4) CODE-F 175. Three identical spherical shells, each of mass m and radius r are placed as shown in figure. Consider an axis XX' which is touching to two shells and passing through diameter of third shell. Moment of inertia of the system consisting of these three spherical shells about XX' axis is :X 177. The two ends of a metal rod are matainted at temperatures 100°C and 110°C. The rate of heat flow in the rod is found to be 4.0 J/s. If the ends are maintained at temperatures 200°C and 210°C, the rate of heat flow will be : (1) 16.8 J/s (2) 8.0 J/s (3) 4.0 J/s (4) 44.0 J/s Ans. (3) Sol. Rate of heat flow µ temperature difference between two ends X' (1) 3 mr2 (2) 16 mr 2 5 (3) 4 mr2 (4) 11 2 mr 5 Þ Ans. (3) X dQ µ (T2 - T1 ) dt Here temperature differnece in both case is same (i.e. 10°C) 1 Sol. 2 Ixx' r r EN So, rate of heat flow will also be same 3 So, X' = I1 + I2 + I3 Hence option (3) 178. Two similar springs P and Q have spring constants KP and KQ, such that KP > KQ. The are stretched, first by the same amount (case a,) then by the same force (case b). The work done by the springs WP and W Q are related as, in case (a) and case (b), respectively : (1) WP = WQ ; WP = WQ (2) WP > WQ ; WQ > WP (3) WP < WQ ; WQ < WP (4) WP = WQ ; WP > WQ Ans. (2) Sol. Given KP > KQ Case (a) : x1 = x2 = x LL 2 2 æ2 2 ö æ2 ö mr + ç mr + mr 2 ÷ + ç mr 2 + mr 2 ÷ 3 è3 ø è3 ø dQ = 4 J/s dt A (Using parallel axis theorem) Þ Ixx' = 2mr2 + 2mr2 = 4mr2 Hence option (3) 176. The electric field in a certain region is acting radially outward and is given by E = Ar. A charge contained in a shepere of radius 'a' centred at the origin of the field, will be given by : (1) A e0 a2 (2) 4 pe0 Aa3 3 (3) e0 Aa (4) 4 pe0 Aa2 Ans. (2) r Sol. Flux linked with sphere = E.dsr since electric field is radial. It is always perpendicular to the surface. so f = Ar.(4 pr 2 ) f = A(a)(4pr 2 ) f = A4pa (as r = a) 3 Now according to gauss law f= q in Î0 Þ qin = f.Î0 1 K x2 WP 2 P K = = P Þ WP > WQ WQ 1 K Q K Q x2 2 Case (b) : F1 = F2 = F For constant force W= F2 1 ÞWµ 2K K so q in = A4pa Î0 WP K Q So W = K Þ WQ > WP Q P Hence option (2) Hence option (2) 3 25 AIPMT-2015 179. A conducting square frame of side 'a' and a long straight wire carrying current I are located in the same plane as shown in the figure. The frame moves to the right with a constant velocity 'V'. The emf induced in the frame will be proportional to : 180. A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is : (1) x (3) I V mk t -1 2 1 -1 mk t 2 2 -1 (2) 2mk t (4) mk -1 2 t 2 Ans. (4) Sol. P = Fv = mav dv dt By integrating the equation Þ K = mv a 1 (2) (2x + a )2 1 (3) (2x - a )(2x + a ) (4) 1 x2 Ans. (3) 2 dv 2k æ 1 - 12 ö = t ÷ dt m çè 2 ø æ 1 ö 2k F = ma = m ç ÷ è 2 ø mt a V x + a/2 A emf Induced in side (1) e1 = B1Vl emf Induced is side (2) e2 = B2Vl emf in the frame = B1Vl – B2Vl e = Vl [B1 – B2] Þ e µ B1 - B 2 Since B µ é ù ê 1 1 ú So e µ ê a aú êx x+ ú êë 2 2 úû é ù 1 1 ú ëê ( 2x - a ) ( 2x + a ) ûú Þ eµê Hence Option (3) 26 2k v2 k t = t Þ v= m 2 m a= LL x–a/2 1 Sol. Þ Hence option (4) x I ò v dv = ò m dt EN 1 (1) (2x - a )2 k Þ 1 r Þ F= mk 2t 2
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